题目内容：

在下列句子的空格处填入适当的内容或括号内单词的正确形式。

1.Police in America have stepped up their search for a 15-year-old boy who went __________ (miss) three days ago in Dover.

2.When asked about the ___________ (possible) that Justin was taken by aliens, Detective Sam told journalists that people sometimes liked to make up such amazing stories.

3.In this peaceful land, people live in perfect harmony _________ nature, far away from the noise and worry of the outside world.

4.Although Mary did not say anything, John assumed that she was linked ________ the incident.

5.She is enthusiastic _________ playing badminton and is now organizing a school tournament.

6.You are supposed _____________   (hand) in your homework tonight.

7.He is making _____________ (prepare) for tomorrow’s exam.

8.All students are ______________ (require) to attend school assembly on Monday mornings.

9.This is the second time that I _________ (lose) my mobile phone.

10.He wastes so much of his valuable time __________ (chat) on the Internet.